Separator coil



Dec. 13, 1938. L. 0. SMITH 2,140,484

SEPARATOR COIL Filed Jilly .8, 1936 Fig.1

- Zmventor Lawrence C. Jm/f/I 6Zze'd KW attorney Patented Dec. 13, 193$ 2,140,484 sarsnsron con.

Iawrence C. Smith, Kenmore, N. Y., assignor to gedders Manufacturing Company, Inc., Buflalo,

YUNlTED' STATES PATENT OFFICE Application July s, 1936, Serial No. 89,528

10mm. (ores-12s) tion line to the compressor for a repetition of the 15 cycle,

The return of the vapor from the evaporator to the compressor has presented aprobl'em in eihcient operation, since the returning vapor should be dry, or completely evaporated. Ii 20 such condition is not obtained, then the suction line will be unduly back-frosted, or the compressor will knock. Neither condition is desirable.- Lubricating oil for the compressor is entrained in the refrigerant in its cyclic passage, and since the relative proportions or states of the refriger- 25 ant and oil are subject to variations with fluctuationsof the work performed by the system, the I matter of providing for mutual satisfactory re- "turn has beena continuing problem.

In the present invention, liquid refrigerant volumes .discharged from the evaporator. are trapped and permitted to evaporate in a separator 0011 which is partially isolated from the more active portions of the circuit by a restricted pas- 35 sage in the form of, a tube of small diameter through which-only gaseous refrigerant may pass. Inasmuch as admixed oil volumes remain in liquid state during this operation, and would eventually be stagnated in the coil and render it ineffective, special provision is made to withdraw .oil. volumes intermittently from the separator coilii'r response to periodic pressure variation conditions Other features of the invention reside in the =simple and economical. structural organization of v "the separator coil with various types of evaporators as more specifically set forth in the specificationandaccompanying drawing, wherein:

' Fig.1 is a side elevation of a domestic evaporam c: the dry type with the separator coil-oi "the-inlvention applied thereto;

, Fig. 2 is a section on the line 2--2 01' Fig. 1; 3 is'aside elevation of a hooded type of I evaporator supplied with a similar type of sepsis.-

Fig.4 isa perspective view of a flat evaporator otthe fdry type having a separator coil formed directlyinto-its'structure; and 4 Fig. 5 is a diagrammatic view of a compressorcondenser-expander type oi refrigeration system showing the separator device of the present invention disposed therein.

Referring first toFig. 5, it may be noted that the compressor-condenser-expander circuit herein considered comprises a compressor A whose discharge line it enters a condenser C wherein the refrigerant is liquefied, to flow to the reservoir R. From this region, the refrigerant is transmitted' through a feed line i and a control valve V to the evaporator E, wherein the liquid refrigerant is more or less converted into gas. The discharge end of the evaporator is connected to the suction side of the compressor through a return lines, and, in accordance with the present invention, the separator device, designated 30 in Fig. 5, is interposed in series relationship with the discharge side of evaporator E and the suction line.

The invention is shown combined with three difierent types ofevaporators, the evaporator Ill oi'Fig. 1 being a domestic unit utilizing the dry system of evaporation and including a continuous coil II formed to encompass partially the sleeves I2 which receive ice cube trays. Liquid refrigerant is introduced into the inlet end I3 of the coil through an expansion valve I4, and is withdrawn in a gaseous state through a suction line I5 which connects to the outlet end I6 of the coil. The evaporator 2Il of Fig. 4 is likewise oi the dry type. and it includes a flat coil 2| which may be enclosed by a sheet metal sheath 22. The inlet and outlet ends of this coil are indicated by the numerals 23 and 24 respectively. In Fig. 3 the evaporator 25 is of the flooded type having a cylindrical header 26 and communicating pipe loops 21 which enclose a sleeve 28. Refrigerant is introduced into the header through a pipe 28, and gas is withdrawn. therefrom through a suction pipe 3| Referring first to the embodiment of Figs. 1 and 2, a separator coil 30 is formed integrally with the evaporator-coil II in the outlet end I8 thereof. The coil 30 is provided with two connected traps or receptacles A and B formed by bending the tubing into vertical legs 32, 33, 34, and 35 connected by looped portions 36, 31 and 38. The exterior legs 32 and 35 forming the receptacle'A are connected at their upper ends by a restrictor tube 40 of relatively small diameter,

ing which the gaseous products of evaporation,

will arise in the legs 32 and 85 for escape through the restrictor tubes 40 or H. The receptacle B provides a second zone of evaporation for any liquid that may escape. from the receptacle A over the loop 31. The evaporation action in this zone substantially duplicates that of the first zone, with the gases passing up the leg 34% and through tube 4|, or directly upward in leg 35 to the suction line.

It will be understood that the described discharge action really occurs in pulsating fashion, and it is occasionally supplemented by periods of more violent activity, when relatively greater volumes are discharged from the evaporator. Advantage is taken of this pressure irregularity to obtain a slight drainage of the separator coil so that oil volumes trapped therein will be removed to allow space for liquid refrigerant. This result is obtained by proportioning the diameter of the tubes 40 and 4| so that their combined areas are suflicient to carry off the evaporated gases when the system is operating at a normal load. Assum-- ing a condition where the tube 40 is inadequate to convey all the products of evaporation, then it will at once be apparent that the resulting increased pressure diflerential across the coil 30 will cause the liquid trapped in the receptacle A to'be forced into the receptacle B. This will un-- block the second tube 4| so that it will :aid the tube 40 to deliver gas to the suction line, and thus decrease the differential and restore the normal operation of the coil 30.

The liquid now conveyed to the receptacle B will undergo a second ebullition action until only an ofl residue remains, and this oil, upon a repetition of a surge or differential condition as above described, will be displaced and forced into the suction line by the incoming volume of liquid from the receptacle A.

The separator receptacles may vary in number and disposal. For example, in Fig. 4, the last tube bend 45 is converted into a receptacle through the provision of a restrictor tube 46, which extends across the legs 41 and 48 of this bend. The leg 48 is formed with an elevated portion 49 to prevent a too rapid drainage of liquid from the bend 45 to the suction line because of its horizontal disposal.

The operation of the separator device of Fig. 4 is similar to that of a single receptacle of the first embodiment, as the liquid trapped in the tube bend 45 is free to boil under only a slight circulatory urge, while the gaseous discharge of the coil is directed through the tube 46. Similarly, in Fig. 3, a single receptacle is provided, and it is formed of tubing having a bend SI and extremities 52 and 53 leading into the header 26 and the suction pipe 3| respectively. A restrictor tube 55 connects the legs of the bend, and it functions in a similar manner to the tubes of the described embodiments.

The several embodiments of the invention heretofore described illustrate but a fewapplications thereof to practical refrigeration problems, which are obviously too numerous to set forth in their entirety. It will therefore be understood that the principles herein set forth may be incorporated in various other manners and systems ends of said tube.

greases I claim: v p

l. A separator device comprising an elongated receptacle forming a well having its ends adapted to be connected with the discharge-side of an evaporator and a compressor suction line respectively, and a restrictor tube having opposite extremities communicating with upper portions .of the ends of said receptacle.

2. A separator device comprising an elongated receptacle forming a well having its ends adapted to be connected with the discharge side of an .evaporator and a compressor suction line respectively, said receptacle having a return bend'formation with its extremities disposed adjacent to each other, and a restrictor tube having its extremities communicating with the upper portions of the ends of said receptacle.

3. A separator device comprising tubing formed into a return bend coil and having inlet and outlet ends adapted to be connected with the discharge side of an evaporator and a compressor suction line respectively, means for mounting said device with the body of the coil disposed at a lower elevation than said outlet end, and a restrictor tube of smaller diameter than the coil tubing and having its extremities communicating with the ends of said coil.

4. A separator device comprising tubing formed into,a coil having a closed return bend, the inlet and outlet ends of said coil being adapted to be connected with the discharge. side of an evaporator and a compressor suction line respectively, said bend being disposed below the level of the inlet and outlet ends, and a restrictor tube connecting said inletand outlet ends.

5. A separator device comprising tubing formed into a coil having a plurality of return bends, the inlet and outlet ends of said coil being adapted to be directly connected with the discharge side of an evaporator'an'd a compressor suction line respectively, said bends being disposed below the level of the inlet and outlet ends, thereby forming a. well, a restrictor tube connecting said inlet and outlet ends, and a second restrictor tube connecting an intermediate section of one of said bends with the outlet end.

6. A refrigeration device comprising tubing formed into a flat coil, inlet and outletends of said coil being adapted to be connected with the discharge side of an evaporator and a compressor suction line' respectively, means for mounting said coil in a horizontal position. a raised formation in the coil adjacent the outlet end thereof, and-a restrictor tube connecting said inlet end to said raised portion.

'1. In a refrigeration system including a compressor, a condenser connected to the discharge side of the compressor, and a. refrigerant evaporator formed with an inlet connected with the condenser and a discharge end connected with the suction side of the compressor, the provision of a separator device interposed in series connection with the discharge end of the evaporator and the suction line of the compressor, said device comprising a loop tube loop having a discharge end portion elevated above the body of said tube, whereby liquid entering therein will be temporarily retained in said tube until withdrawn by a pressure diflerential established between the evaporator and the compressor, and a restrictor tube of small diameter compared to'the diameter of said tube connecting the inlet and discharge LAWRENCE C. SMITH. 

